Using 3 criteria, not sure of syntax and what I am doing wrong

I am trying to look up the site code, if a space is a lab, and what BU, all 3 a separate columns on the same sheet - the first two are on a summary sheet successfully as

=COUNTIFS({WDC Lab Inventory_WDC Site Code2}, $[WDC Site Code]@row, {WDC Lab Inventory_Lab Space or Office Space}, "lab")


But then when I try to add the third criteria, I am not sure how -

=COUNTIFS({WDC Lab Inventory_WDC Site Code2}, $[WDC Site Code]@row, {WDC Lab Inventory_Lab Space or Office Space}, "lab", [{WDC Lab Inventory_WDC Site Code}, [WDC Site Code]6, {WDC Lab Inventory_Business Unit}, [Content Solutions]$])


Appreciate the help

Answers